(a) General. Upon receipt of a complete request, the PBGC shall notify the plan sponsor in writing of the date of commencement of the 90-day period specified in section 4220 of ERISA. Except as provided in paragraph (c) of this section, the PBGC shall approve or disapprove a plan amendment submitted to it under this part within 90 days after receipt of a complete request for approval. If the PBGC fails to act within the 90-day period, or within that period notifies the plan sponsor that it will not disapprove the amendment, the amendment may be made effective without the approval of the PBGC.

(b) Decision on request. The PBGC's decision on a request for approval shall be in writing. If the PBGC disapproves the plan amendment, the decision shall state the reasons for the disapproval. An approval by the PBGC constitutes its finding only with respect to the issue of risk as set forth in section 4220(c) of ERISA, and not with respect to whether the amendment is otherwise properly adopted in accordance with the terms of ERISA and the plan in question.

(c) Suspension of the 90-day period. The PBGC may suspend the running of the 90-day period referred to in paragraph (a) of this section if it determines that additional information is required under § 4220.3(e). When it does so, PBGC's request for additional information will advise the plan sponsor that the running of 90-day period has been suspended. The 90-day period will resume running on the date on which the additional information is received by the PBGC, and the PBGC will notify the plan sponsor of that date upon receipt of the information.